Re: [Boost-users] Subject: Serialization, text_Xarchive Why doesn't work?

From: Konstantin Tkachenko (tkachenkok_at_[hidden])
Date: 2006-08-03 11:49:20

That is not a greate problem.

The problems start then...

The reason of the problem can be follow:
one of the operator [](int Index) has two versions, which have only one difference:
const OTCValue& and OTCValue&.

Maybe the compiler cannot choose the necessary.

But now I have another problem:
I have such a class, which shouldn't be saved normally (OTCData).
The reason for this: this class has a member, which should be rerialized via string, more then that, it cannot be copied (OTCDataID and OTCDataHeaderID).

So I've tried to do following:

#include <boost/serialization/tracking.hpp>
#include <boost/serialization/split_member.hpp>
namespace DataManagement
{
    class OTCData : public IOTCData
    {
        friend class boost::serialization::access;
        template<class Archive>
            void save(Archive & ar, const unsigned int version) const
        {
            const std::string own_id=m_own_id->save_to_string();
            ar & own_id;
            const std::string header_id=m_header_id->save_to_string();
            ar & header_id;
            ar & m_rows;
            ar & m_cols;
        }
        template<class Archive>
                void load(Archive & ar, const unsigned int version)
        {
            std::string own_id;
            std::string header_id;
            ar & own_id;
            m_own_id->load_from_string(own_id);
            ar & header_id;
            m_header_id->load_from_string(header_id);
            ar & rows;
            ar & m_cols;
            
        }
        BOOST_SERIALIZATION_SPLIT_MEMBER();

        std::auto_ptr<OTCDataID>    m_own_id;
        std::auto_ptr<OTCDataHeaderID>    m_header_id;
        std::vector<OTCRow>        m_rows;
        int            m_cols;
// shouldn't be serialized
        const IOTCDataHeader *    m_header;
        };
}

Then function to save instance of OTCData:

namespace DataManagement{
  class DataController
  {
     void save_otcdata(const OTCData&data)const;
  };

  void DataManagement::DataController::save_otcdata(const OTCData& data) const
  {
        std::string file_name=set_file_name(data);
        std::ofstream	ofs(file_name.c_str());
        boost::archive::text_oarchive oa(ofs);
        oa << data; // Here I have very long compiler error messages
        // which are very like the messages by trying to save nonconstant object 	
  }
}

I have no idea any more. I save only constants and the compilation fails!

Thanks to all!

-------- Original-Nachricht --------
Datum: Thu, 3 Aug 2006 08:14:41 -0700
Von: "Robert Ramey" <ramey_at_[hidden]>
An: boost-users_at_[hidden]
Betreff: Re: [Boost-users] Subject: Serialization,	text_Xarchive Why doesn\'t work?

> Is it possible that m_value is uninitialized?  It is a known
> problem that many compilers can can write uninitialized
> floating/double values to a text stream and then cannot
> read them.  This topic is currently being discussd on
> the developer's list - as it arises all the time.
> 
> Take a look a test_serial.txt with a text editor.
> What does it look like?
> 
> Robert Ramey
> 
> tkachenkok_at_[hidden] wrote:
> > I've tried to write my first application with Boost.Serialization
> > library.
> >
> > Here is the part of code, where the boost::text_iarchive throws an
> > exception "boost::archive::archive_exception" "what():  stream
> > error":
> >
> > [code]
> > enum Origin {
> >     UNKNOWN=0,
> >     MEASURED,
> >     AVERAGE };
> >
> > class OTCValue
> > {
> > friend class boost::serialization::access;
> > template<class Archive>
> > void serialize(Archive & ar, const unsigned int version)
> > {
> > ar & m_value;
> > ar & m_orig;
> > }
> > double m_value;
> > Origin m_orig;
> >         ...
> > };
> >          ...
> > const OTCValue val1=(*loaded.second.begin())->get_row(0)[0];
> > {
> > std::ofstream ofs("test_serial.txt");
> > boost::archive::text_oarchive oa(ofs);
> > oa << val1;
> > }
> > OTCValue val;
> > {
> > std::ifstream ifs("test_serial.txt");
> > boost::archive::text_iarchive ia(ifs);
> > ia >> val; // here is this exceptions thrown
> > }
> >         ...
> > [/code]
> >
> > And here is a little bit different code, which works great:
> >
> > [code]
> > enum Origin {
> >     UNKNOWN=0,
> >     MEASURED,
> >     AVERAGE };
> >
> > class OTCValue
> > {
> > friend class boost::serialization::access;
> > template<class Archive>
> > void serialize(Archive & ar, const unsigned int version)
> > {
> > ar & m_value;
> > ar & m_orig;
> > }
> > double m_value;
> > Origin m_orig;
> >         ...
> > };
> >          ...
> > const OTCValue val1(5.5, MEASURED);
> > {
> > std::ofstream ofs("test_serial.txt");
> > boost::archive::text_oarchive oa(ofs);
> > oa << val1;
> > }
> > OTCValue val;
> > {
> > std::ifstream ifs("test_serial.txt");
> > boost::archive::text_iarchive ia(ifs);
> > ia >> val;
> > }
> >         ...
> > [/code]
> >
> > What is the problem? The construction
> > (*loaded.second.begin())->get_row(0)[0] returns an OTCValue .
> >
> > I have compiled the boost-1.33.1 from the sources (www.boost.org).
> > The project I've made is under KDevelop 3.2.2 (initially consol
> > "Hello World" application)
> >
> > Operating System: SuSe Linux 10.0
> > Compiler: gcc version 4.0.2
> >
> > I hope, that I've gave enouph information. If not, ask what aou need,
> > you are welcome.
> >
> > Best regards,
> > and thanks to all! 
> 
> 
> 
> _______________________________________________
> Boost-users mailing list
> Boost-users_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users

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